The first week of April is the time to think about planting. Think about what seeds you want to start indoors for setting out later; think about what annuals you’ll want to grow for summer color and think about what perennials and new trees and shrubs you’ll want to add.

Then head to the nursery and think about which plants are cold hardy enough to plant this month.

If you want color and you want it now, head for the perennial section. You’ll find bright eye candy in the form of rock-garden plants that are not only tough enough to handle freak cold and hail storms waiting to strike, but flower well in rocky soil as long as they get full sun and good drainage.

The bright colors of blooming rockery plants are almost too vivid to be real. The night-glowing white of candytuft (Iberis) makes even Donny Osmond’s smile look dull. The brilliant yellow of Basket-of-gold (Aurinia) is a low-growing rockery plant that will survive in the poorest of soils and yet blast out color so yellow the birds will need sunglasses. Then there is Aubrieta. This gray-leaved, drought-resistant perennial blooms in the chinks of stone walls or gravel walkways with petals so purely purple you’ll think they were dipped in grape juice.

You’ll find plenty of delicious spring color ready to plant now if you visit nurseries that sell rock garden perennials – and plenty of other tough plants that don’t mind the cold. Warning: It is still too early to plant geraniums, fuchsias, coleus and warm season annuals outdoors – even if you do see them for sale.

Q I want to plant a row of evergreen shrubs called “Green Giant” thuja. How far apart should I space the plants to form a solid hedge?

A Are you sure you have enough room for “Green Giants?” These evergreen arborvitae grow 5 feet a year and can become 20 feet wide and 50 feet tall. They can be sheared to keep them in bounds, but that is one pruning job that can keep an army of full-time gardeners busy all summer long.

The Emerald or ‘Emerald Green’ Thuja arborvitae are more compact and practical as a living green wall. They grow only 4 feet wide over time. Spacing of hedge plants depends on how large they are when planted and the mature width of the plants. Figure three feet apart for the compact Emerald Green Thuja and 10 to 15 apart for the ‘Green Giants.’

Q When can I plant pumpkin seeds? We saved the pumpkin seeds from our Jack-O-Lantern last fall.

A Wait a few more weeks, then start your pumpkins indoors so you can set the young seedlings outside around the middle of May when all danger of frost is past. Warm-season plants like squash, tomatoes and eggplant don’t like to be started too soon inside the house. They start reaching for the sunlight as they grow and then forget about their day jobs and start turning into show girls – tall and leggy with no sense at all. Mid-April is a good time to start these warm-season crops indoors.